Boom Supersonic jet breaks sound barrier to open way for new ‘Concorde’
More than two decades after the last commercial supersonic flight, US start-up’s trial aircraft breaches Mach 1 in California
A test aircraft built by a US start-up has broken the sound barrier for the first time during a flight, potentially paving the way for the return of supersonic commercial travel more than 20 years since Concorde’s final flight.
Boom Supersonic’s XB-1 successfully exceeded Mach 1, about 770 miles per hour, after reaching an altitude of 34,000 feet above the Mojave desert in California on Tuesday.
The Denver-based company, which is backed by several US tech investors including OpenAI’s Sam Altman, said the flight marked the first time an independently developed jet, rather than one backed by governments, had broken the sound barrier.
Boom, founded in 2014 by chief executive Blake Scholl, hopes to begin carrying passengers on its commercial airliner, Overture, as early as 2029.
Speaking before the flight, Scholl hailed it as a milestone.
“It’s hard to overstate. It’s been 22 years since we’ve had a civil supersonic flight. The industry has gone backwards and today we are back.”
The era of supersonic commercial flying came to an abrupt end in 2003 with the retirement of Concorde. The aircraft’s high fuel consumption made it extremely expensive to operate, while its loud noise limited its flight paths to transatlantic routes.
A fatal crash in July 2000 led to the grounding of the entire fleet for almost a year. The September 11 terrorist attacks the following year, which led to a widespread slump in passenger travel, proved to be the final straw for operators British Airways and Air France, prompting the carriers to close down the Concorde programme.
Before Tuesday’s flight, Boom had performed 11 test flights with XB-1 since March last year, most recently reaching speeds of Mach 0.95 — just below the supersonic threshold of Mach 1 or one times the speed of sound.
The XB-1 is about one-third the size of the Overture jet that Boom hopes to use for passenger flights. Designed to carry 64 to 80 passengers, the plane would be smaller than the average commercial airliner today and would cost about $200mn. The company has already secured orders and pre-orders from United Airlines, American Airlines and Japan Airlines to purchase 130 aircraft.
Boom is developing its own engines for the Overture together with Kratos Defense & Security Solutions, which helped design turbines for the F-22 and F-35 fighters.
If successfully developed, Boom’s plane will be capable of flying at Mach 1.7 — twice the speed of today’s fastest commercial aircraft built by Airbus or Boeing. That could allow the aircraft to halve some flight times, making trips between London and Miami in just under five hours and Los Angeles to Honolulu in three hours. It would be designed to fly more than 600 routes around the world.
Despite Tuesday’s success, taking the project from test stage through to development and launch will be both a technical and financial challenge. Boom is one of the few commercial players still standing. Aerion Supersonic, whose backers included Lockheed Martin and Boeing, collapsed in 2021. Another company, Exosonic, shut down in November last year.
Boom’s latest $100mn funding round brings its total backing from investors to almost $600mn. Alongside OpenAI’s Altman, backers include financial trader Alex Gerko, founder of XTX Markets, and Reid Hoffman, co-founder of LinkedIn.
The company has also received more than $250mn from additional sources, including the US Air Force and non-refundable deposits from its airline customers.
Some airline executives privately question whether there is any need to return to supersonic air travel — always a niche business when Concorde was operating — particularly given the industry’s struggle to decarbonise.
Scholl said he believed the market for Overture could be “easily over 1,000 aircraft”.
“If we can solve affordability, sustainability and safety, then everyone wants supersonic . . . This [aircraft] builds on decades of progress since the last time we built a supersonic jet,” he added, noting that neither Boeing nor Airbus had built a new plane for 20 years.
Boom expects airlines to be profitable at about $5,000 a seat.
Overture, said Scholl, would be built using new materials such as carbon fibre and would be more fuel-efficient than Concorde. Its engines would also be able to fly sustainable aviation fuel.